Steam-generator.



A. A. E. STERZING.

STEAM GENERATOR.

APPLICATION FILED IULY II, I9I5.

1,275,492. PandAug.13,1918.

UVV v /MvW//// 11 o)11 1111 11 @1 1011011011011 1I1111Q11M11 OOOOO ALBERT A.. E. srEazING, or NEW YORK, N. Y.

STEAM-GENERATOR.

Specification of Letters Patent.

Patented Aug. 13, 191s.

Application led J'uly 17, 1915. Serial No. 40,357.

To all whom t 'may concern:

Be it known that I, ALBERT A. E. Srnnz- ING, a subject of the King of Great Britam, and a resident of the city, county, and State of New York, have invented certain new and useful Improvements in Steam-Generators, of which the following is a spec1fication.

This invention relates to an apparatus designed for the heating of water and the conversion thereof into steam, and it consists chieiy of improvements upon and additions to the steam-generator disclosed by me in Letters Patent of the United States No. 1,049,546, issued on lthe 7th day of January,1913. c

The patent aforesaid covers an apparatus wherein a combustion chamber is combined with a plurality of water-heating and steamgenerating elements connected together in series, and arranged in superposed relation in such a manner as to plresent between them a sinuous passage to t e products of combustion. The present invention is principally concerned with the structural design and manufacture of these elements.

In accordance with the preferred construction set forth in the said patent, each of the water-heating and steam-generating elements consists of three parallel plates, the outer ones of which are secured together at the edges, and separated from the intermediate plate to form plural spaces having large areas of heating surface in proportion to their volume. The latternamed plate is held in place by means of rivets and distance pieces arranged at intervals throughout the intermediate portions of the element so as to take up theA pressure on the outer plates and hold the parts in their proper relative positions. While the construction just outlined fully answers the purpose contemplated by the patent, it will be observed that the distance pieces take up twice as much room as the stems of the rivets, and they impede more or less the flow of water to the stems, besides causing somefriction that tends to retard the flow. One of the objects, therefore, of the improvements forming the subject-matter hereof is to provide a novel structure for the said element by virtue of which the plates and rivets comprised in the same are so combined, assembled, and united that they derive from one another the mutual support necessary to eiect a them free access to the stems of tion is to be found in a solid, effective, and durable construction,

without the use of intermediate distance pieces whatsoever, that is, such as are related to the rivets or similar fastenings.

A peculiarity of the element const ,noted as above mentioned is that the rivets xthere- 1n are upset intermediately of their stems While the severa] plates are joined together, and shoulders are formed on th'e'stems at polnts contiguous to the opposite sides of the. several j plates around the holes through whlch the rivets are passed. These shoulders lill the twofold object of maintaining the platesl at appropriate intervals apart and aifordmg to the water flowing between the rivets.

Another d1st1nguishing feature of the invention, as embodied in the said element, resldes in the shape given to the rivet heads by means of which a considerable increase of surface is obtained for contact both with the gases or products of the plates and with combustion.

Still another characteristic of the invenpeculiar grou in4 of the rivets in and out of the plates, wliic causes the water as well as the gases of com- I bustion to be diverted from astraight course, so that more heat is yielded by the latter and consequently absorbed by the former.

The various objects and advantages above expressed, or implied, are conveniently realized through the use of the invention in the form hereinafter described in detail, and illustrated in the annexed drawings', in which- Figure 1 is a sectional plan of part of a generator disclosing someL of the said improvements;

Fig. 2 is a section of one of the steamgenerating elements, taken lengthwise of the plates; and v j Fig. 3 is a section of the same element bisected in a transverse direction.

Speaking of the water-heating and steamgenerating elements as articles of manufacture, it will be noted that each element comprises, preferably, three'plates,.21 22 and 23, placed in parallelism at substantially equal distances apart, and held together by rivets of peculiar configuration, disposed in various series, as hereinafter particularized. No single element is shown in full, otherwise than in plan, Fig. 1, as this is not necessary for an intelligent comprehension of the poses a larger improvements herein revealed, and a com plete disclosure of the potential constituent parts of such elements is afforded to the reader by Patent No. 1,049,546, before cited to which reference is hereby made for all data that may be desired in that respect.

Each one of the said rivets includes the following-named parts, to wit: a stem 26, adapted to be plassed through alined holes in said plates; eads 27 and 28, designed to bear upon the outer plates, on opposite sides of the element, respectively; and shoulders or abutments 29, intended to maintain the several plates rigidly at fixed distances apart from one another.

By preference, the rivet heads 27 and 28 are both made oblong and curved as shown, so that by setting their narrow portion in the width of their respective plates they will offer practically no obstacle to the rapid flow of the ases of combustion, when the element is rightly positioned in the generator. As explained in the saidpatent, the How occurs in a longitudinal direction relatively to the plates. The oblong shape given to the headsit will be observed,x exarea to contact with the hot gases than is afforded by either a round or a conical head, and this shape further prevents accumulation of soot or fine ashes at the back of the heads. Besides affording a large superficial area of active heat transmission, the oblong heads also permit a close grouping of the rivets transversely of the plates in each element, by setting their said heads with the major axis thereof parallel to the elements longest dimension.

The rivet heads that underlie the bottom plate of the element' are formed before the insertion of the rivets into the holes of the three plates, and therefore, as shown in Figs. 2'and 3, they can be made materially longery than the heads subsequently formed at the opposite ends of the rivets over the top plate. The latter-named heads may either be swaged withl a special die at the time of riveting the plates together', or else be made up in the'manner suggested on the right-hand side of the said Figs. 2 and 3, where a rivet head 31 is shown as being rst made flat, and afterward built upon to produce the desired curves. The fiat shape, indicated by the sectional part of the head, is obtained, of course, more readily than the other. The curved top, represented by the u nshaded portion, is subsequently added on either by acetylene welding or according to the Goldschmidt method of pouring hot metal into a. form, applied to the flat head previously hammered to shape.

As hereinbefore stated, it is not intended in the present invention to use distance pieces in connection with the rivets to provide intermediate supports for the plates of which the water-heating and steam-generatirig elements are formed. The omission of these adjuncts to the rivets, like the shape of the heads above spoken of, allows a much closer grouping of the rivets than could be effected otherwise. In fact, the rivets can be grouped as close to one another as the strength of the plates will allow. Thus, the combined surfaces of the stems exposed to the water inside of an element, and similarly the cumulated surfaces of the rivet heads encountering the hot gases of combustion outside of the element, may considerably surpass the aggregated areas of the plates themselves. l

Compared with the spacing of rivets illustrated in Fig. 2 of the said Patent, No. 1,049,546, where the are arranged in parallel rows staggere in ordinary fashion, the grouping provided for in the present invention includes two additional lines of rivets between the staggered rows. This is clearly seen in Fig. 1 of the drawings hereto annexed, wherein the upper portion of the lower element is shown without the additional rivets by wa of contrast and in which the correspon ing portion of the upper element, besides the lines of rivets marked 34 and 35, common to both elements, comprises other lines designated by 36 and 37 made up of added rivets. The interposition of the latter causes the rivets to be gathered in series of twos, or threes, or fives, respectively indicated by the reference numerals 38, 39 and 40. It will be noted that the divers series run obliquely across the plate and in different directions. This mode of spacing, though suggestive of an apparent disorder, is, nevertheless, the result of a preordained arrangement and produces what may be termed a regular irregularity in the disposition of the rivets, the peculiar grouping of which in various clusters deviates both Athe water and the hot gases of combustion and compels them to travel along tortuous paths that impede their progress suiiciently to obtain either the heating of the water or its vaporization in the least possible length of time.

The before-mentioned shoulders or abutments 29 are formed on the rivet stems 26 as soon as the latter have been passed through the alined holes in the superposedV plates 21, 22 and 23. As will be understood, the rivets are brought to a red heat prior to their insertion in the holes, and when set in place they are struck with'a hammer in order .to form the upper heads 28. The blows cause the red hot stems to swell out into beveled recesses provided in the inner faces of the top and bottom plates, and in both faces of the intermediate plate, as indicated in Fig. 2, the stem portions that intervene vbetween the several shoulders or abutments being meanwhile thickened and forced against surrounding sockets forming tools which also have recesses adapted to register with those in the plates.

The invention in its broader aspects is not restricted to the exact construction herein set forth, as it is manifest that several changes can be eil'ected in the same without departing from the main principles of the invention or even sacrificing any of its chief advantages.

I claim:

1. An element of the character described including a plurality of superposed plates, and rivets therefor having oblong heads the major aXes whereof lie longitudinally of said plates.

2. An element of the character described including a plurality of plates disposed one above another in parallelism, rivets therefor arranged in parallel rows lengthwise of said plates, and heads of reduced width on said rivets permitting a serried grouping thereof in a transverse direction.

3. An element of the character described including a plurality of plates positioned in superposed relation, parellel lines of rivets holding said plates in their respective positions, and additional rivets crossing said lines so as to form therewith clusters running in oblique directions.

4. An element of the character described including a plurality of superposed plates suitably spaced apart, rows of rivets holding said plates together, and other rivets combining to form with said rows clusters extending obliquely in reverse directions.

5. An element of the character described including a set of three plates to be maintained apart in super-posed relation, and rivets therefor having stem enlargements capable of holding the middle plate in its assigned position.

6. An element of the character described including a series of three plates to be held together in parallelism and rivets therefor having integral abutments capable of supporting. the middle one of said plates.

An element of the character described including a plurality of plates arranged in su erposed relation, and rivets therefor annu arly expanded adjacent to the inner surfaces of said plates.

In testimony whereof I have signed my name to this specification.

ALBERT A. E. STERZING. 

